TuRRiTis. XIII. CRUCIFERiE. 165 



1. N. OFFICINALE. R.Br. (Sisjanbrium Nast. Z/mw.) English Water Cress, 

 lyvs. pinnate; Ifts. ovate, subcordate, repand; pet. white, longer than the 



calyx.— 7|. Brook.s and ponds. Steins decumbent If long, thick, with axillary 

 branches. Leaves of 3—7 leaflets ; leaflets broad, often cordate, rather acute, 

 obtusely toothed, terminal one largest. Flowers corymbed. Siliques less than 

 1' long. Jn. — It is beginning to be cultivated in the vicinity of our cities as a 

 salad. ^:|: 



2. N. AMPHiBiUM. R. Br. (Sisymbrium. Linn.) AniphiMous Water Cress. 

 Lvs. oblong-lanceolate, pinnatifid or serrate; rt. fibrous ;;?e^. longer than 



the calyx ; siliq^ie elliptical, acute at base, tipped with the mucronate style.— 

 % Banks of the Mohawk, Dr. Robbins. Rare. Stem 1— 2f high, furrowed. 

 Leaves variable, immersed ones pinnatifid or pectinate, upper ones serrate. 

 Flowers yellow, minute, in a long, dense raceme. Silique half as long as the 

 spreading or reflexed peduncle, pointed with the short style. Jn. Jl. 



3. N. PALUSTRE. DC. Marsh Watei- Cress. 



Lvs. pinnately lobed, amplexicaul, lobes confluent, dentate, smooth ; rt. 

 fusiform ; pet. as long as the sepals ; siUqxie spreading, turgid, obtuse at each 

 end.— Tj. In wet places. Stem 1— 2f high, erect, branched above. Leaves ^—3 

 long, all more or less pinnatifid, smooth, except a few ciliae at base. Flowers 

 numerous, minute, yellow. Silique 3 — 4" long, on pedicels of equal length. 

 Jn. — Aug. 



4. N. HispiDUM. DC. (Sisymbrium. Pairet.) Hispid Water Cress. 



St. villous ; lvs. somewhat villous, runcinate-pinnatifid, lobes rather ob- 

 tusely dentate ; siliqiies (rather silicles) ovate, tumid, pointed with the style, 

 scarcely more than half as long as the pedicels; pet. scarcely as long as the 

 calyx.— 7|. Banks of streams, Walpole, N. H., Conn, to Penn. Stem angular, 

 branched, 1 — 3f high, with many paniculate racemes above. Leaves 3 — 6 

 long. Flowers minute, yellow. Silicles l" long, on pedicels 2—3" long and 

 somewhat spreading. 



5. N. NATANs. DC. p. Americanum. Gray. Floating Water Cress. 

 Emersed lvs. serrate, oblong-linear, undivided, immersed ones doubly 



pinnatifid, with capillary segments ; pet. twice as long as the calyx ; siliques 

 obovate, twice as long as the style. — "Zj. In water, Can. and U. S. Stem long, 

 submerged. Flowers white, middle size. Jl. 



6. N. SYLVESTRE. (Sisymbrium vulgare. Pers.) Creeping Water Cress. 

 Lvs. pinnately divided, segments lanceolate, incisely serrate ;j?ef. longer 



than the calyx ; siliques oblong, torulose ; slij. very short. — Banks ot the Dela- 

 ware near Philadelphia. Nuttall. ^ 



13. BARBAREA. R. Br. 



In honor of St. Biirbara, who discovered (what no one has since perceived) its medicinal virtues. 



Sepals erect, subequal at base ; silique columnar, 2 — 4-cornered : 

 valves concave-carinate; seeds in a single series ; 0=. — Lvs. lyratcly 

 pmnaiijld. Fls. yellow. 



B. VULGARIS. R. Br. (En'simum Barbarea. Linn.) Winter Cress. 



Lower lvs. Ivrate, the terminal lobe roundish, upper ones obovate, pin- 

 nntifid at ba.se, crenate or rcpand-dentate ; siliqms obscurely 4-cornered.— 'Ij. In 

 old fields, also brook-sides. Northern States, W. to Oregon, common. Whole 

 plant glabrous. Stem furrowed, 1— 2f high, branching above. Leaves 1—3 — 4 

 long, dark green, .shining, on clasping petioles, the terminal lobe 1— U' diam., 

 upper ones se.ssile, all with olttuse teeth. Flowers on pedicels \' long, in ter- 

 minal racemes. Siliques slender, }' long, curved upwards. May, Jn. 



14. TURRITIS. DUlon. 



Lnt. tvrritia, turrcted ; from the jiyromidnl form of the plant. 



Sepals erect, converginf^ ; petals erect ; silique long, linear, 2-edgea ; 

 valves plane : seeds in a double series, 0=. — Fh. cyanic. 



